165231261 has 24 divisors (see below), whose sum is σ = 259540736. Its totient is φ = 100686240.

The previous prime is 165231223. The next prime is 165231281. The reversal of 165231261 is 162132561.

165231261 is a `hidden beast` number, since 1 + 652 + 3 + 1 + 2 + 6 + 1 = 666.

It is not a de Polignac number, because 165231261 - 2¹⁷ = 165100189 is a prime.

It is a super-2 number, since 2×165231261² = 54602739223300242, which contains 22 as substring.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165231281) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5196 + ... + 18906.

Almost surely, 2^165231261 is an apocalyptic number.

It is an amenable number.

165231261 is a deficient number, since it is larger than the sum of its proper divisors (94309475).

165231261 is a wasteful number, since it uses less digits than its factorization.

165231261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13833 (or 13830 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 165231261 is about 12854.2312488923. The cubic root of 165231261 is about 548.7367824574.

The spelling of 165231261 in words is "one hundred sixty-five million, two hundred thirty-one thousand, two hundred sixty-one".